A blade server aims to accommodate a greater number of small server units in a smaller space. It is a server cluster adopting a modular design. The server is thin and formed like a blade, and can be inserted and removed easily. The entire module is like a small box, and the servers are inserted in the box like individual blades. As insertion and removing are easy, expandability is greater. Users can add a number of “blade modules” according to requirements. For instance, a small box originally containing six blade servers can be coupled with another box of six blade servers. Such a modular design has a shorter connection line among the servers than the conventional ones, and also is easier to repair and maintain. To meet the requirements of high speed processing and low operation cost in industries, a new type of blade server has been developed that can hold maximum eight blades in a 4U chassis (1U is 1.75 inches) to equip 64 bits high speed processing power. Such a blade server can minimize IT setup cost and maximize service level. In addition, the blade server can be configured into a “virtual super computer” and is very desirable to be used in academic and research institutions that require huge processing power. For service providers, the blade server can provide various hosting services, such as Server Farm. For content providers, the blade server can be clustered to transmit a great amount of contents. In multimedia industry which has to process a huge amount of information, such as streaming media, the blade server offers a best platform with capability to transmit a great amount of information. The blade server also can substitute or aid many existing server environments that use individual and separated servers. Management and expansion of blade server also is easier. Hence processing resources can be allocated more efficient. In short, due to the blade server adopts centralized management rather than provides a keyboard and a monitor for each set of blade server, server providers can offer and sell more management software. As software usually has a higher gross profit than hardware, the server providers can enjoy a higher profit. Moreover, as the economic condition improves and network machine room space is constrained, enterprises have to save space while meeting the increasing demand. In addition, the blade server can meet the requirement of capacity on demand of enterprises gradually without replacing the entire system. Take into account of all these factors, the blade server will gradually replace the pedestal server which takes more space, and rival the rack mount server.
Patents for blade servers are known in the art. For instance, in R.O.C. patent publication No. 543799, Applicant discloses a “High density server module” in which a plurality of layers of small servers are mounted on a front side and a rear side to form a super computer to process a great amount of data. It mainly includes a holding unit divided into a plurality of casings that have space for holding and unloading small servers, a cooling unit located in the casings and an outer cap covering the upper side of the casings. The server module can be coupled with a plurality of small servers to form a super computer to process huge amount of data.
However, the blade server also has drawbacks: while some server providers have offered relatively open PCI module to be used on PCI add-on card, most still adopt proprietary specifications of blade backplane interfaces. Refer to FIG. 1 for a schematic view of a conventional blade server. It has a chassis with a power supply system on a rear end and a plurality of small servers on a front end. There is a power integration panel interposed between the power supply system and small servers. To maintain uninterrupted power supply while removing and replacing a damaged or targeted small server in a hot plug condition, the existing technique has to provide a power input port on the logic processing main board in the small server mating a coupling port on the power integration panel. It usually adopts a gold finger. But with constant advance of software and hardware, especially CPU and main board for logic processing, the design of the power input port on the logic processing main board under the existing technique for the general server or personal computer cannot be adopted on the small servers of the blade server. Moreover, component providers have to design and fabricate the logic processing main board according to special specifications of one customer, fabrication cost is higher. Without common customers, inventory is limited. For enterprise users, compatibility of the existing IT architecture or future upgrade is a big concern. In the event of malfunction occurs to the logic processing main board, replacement of the logic processing main board could be a big problem. Hence although the blade server has many benefits, it is still not widely adopted among enterprise users. Hence market acceptance of this type of product is still limited.